Translate ASCII text to braille

Python - 90 75 + 50 = 125

Use lower case letters.

for l in input():
 a=ord(l)-96
 if a<0:a=0
 print("⠀⠁⠃⠉⠙⠑⠋⠛⠓⠊⠚⠅⠇⠍⠝⠕⠏⠟⠗⠎⠞⠥⠧⠺⠭⠽⠵"[a],end="")

One-liner (thanks to ɐɔıʇǝɥʇuʎs)

for l in input():print("⠀⠁⠃⠉⠙⠑⠋⠛⠓⠊⠚⠅⠇⠍⠝⠕⠏⠟⠗⠎⠞⠥⠧⠺⠭⠽⠵"[max(0,ord(l)-96)],end="")

Python, 162

l=map((" a c,bif/e d:hjg'k m;lsp o n!rtq%12s. w -u x v   z y"%'').find,raw_input().lower())
for i in 1,4,16:print'  '.join('.o.o    ..oo'[(n&i*3)/i::4]for n in l)

Currently supports lowercase letters and some punctuation, but it's still a work in progress.

Example:

$ python braille.py
Hello, world!
o .  o .  o .  o .  o .  . .  . .  . o  o .  o .  o .  o o  . .
o o  . o  o .  o .  . o  o .  . .  o o  . o  o o  o .  . o  o o
. .  . .  o .  o .  o .  . .  . .  . o  o .  o .  o .  . .  o .

BBC Basic 103 ASCII characters or 92 tokens

A$="HXIKJY[ZQShxikjy{zqsl|Wmon"FORK=1TO26A=ASC(MID$(A$,K))VDU23,K+96,A AND9;0,A/2AND9;0,A/4AND9;:NEXT

Possibly not quite what the OP intended, this redefines the font for the lowercase characters. VDU 23,n,a,b,c,d,e,f,g,h assigns an 8x8 bitmap to character n, consisting of eight bytes. Following a parameter with a semicolon instead of a comma causes it to be treated as a two-byte little-endian number.

The braille patterns for letters a through z are stored in A$, according to the following bit pattern. This is extracted by masks with 9=binary1001 and rightshifts (division by 2 and 4 is used as standard BBC basic has no shift operator.)

 8 1
16 2
32 4

Ungolfed code

A$="HXIKJY[ZQShxikjy{zqsl|Wmon"
FORK=1TO26
  A=ASC(MID$(A$,K))
  VDU23,K+96,A AND9;0,A/2AND9;0,A/4AND9;
NEXT

Usage example

This is done in screen mode 6 for clarity (type MODE6 as soon as you open the command line emulator.)

Actually, after running the code, any lowercase letters (including keyboard input) appear in Braille.

Emulator at http://bbcbasic.co.uk/bbcwin/bbcwin.html.

See also this similar answer of mine: https://codegolf.stackexchange.com/a/28869/15599